Alfonso Cuaron's 3D space epic Gravity took flight Thursday night at the North American box office, grossing a pleasing $1.4 million as it sets out to cross $40 million in its debut.

Starring Sandra Bullock and George Clooney, Gravity has generated enormous buzz after screening at all three of the marquee fall film festivals (Venice, Telluride and Toronto). The film -- easily expected to win the weekend -- cost roughly $100 million to produce, and is selling a higher percentage of 3D tickets (91 percent) than any title in Fandango's history, including James Cameron's Avatar.

Last month, horror pic Insidious 2 grossed $1.5 million in Thursday night runs on its way to a $40.3 million opening.

Gravity revolves around two astronauts left floating in space when their space shuttle is damaged (Bullock has a far bigger role). Producers include David Heyman, who played a key role in the Harry Potter franchise.

The only other new wide player this weekend is New Regency and 20th Century Fox's gambling thriller Runner Runner, starring Justin Timberlake and BenAffleck. Runner Runner is tracking to open in the $10 million to $12 million range after taking in only $200,000 Thursday night. The saving grace is the film's reported $30 million budget.

Adding intrigue to the weekend, Sony has decided to sneak Paul Greengrass' Somali pirate drama Captain Phillips, starring Tom Hanks, into 800 theaters on Saturday night a week ahead of its opening. Both Captain Phillips and Gravity are considered awards contenders.

Runner Runner was directed by Brad Furman and also stars Gemma Arterton and Anthony Mackie. New Regency, which fully financed the film, partnered with Leonardo DiCaprio's Appian Way on the project.

The film, from a script by Brian Koppelman and David Levien(Rounders), revolves around a Princeton University student (Timberlake) who is lured into an Internet poker scam by the owner of a popular gambling website (Affleck).